1. Field of the Invention
The present invention relates to the field of display technology, and more particularly, to a method for image display and a display system adopting the method.
2. Description of the Prior Art
Nowadays, a red (R) subpixel, a green (G) subpixel, and a blue (B) subpixel form a pixel for an image display device such as a liquid crystal display (LCD) panel and an organic light-emitting diode (OLED) panel. Any required colors can be successfully mixed and obtained to show colorful images by controlling the grayscale value of each of the subpixels. With the development of information technology (IT), demands for display panels with various features are increasing such as high rate of penetration, low power consumption, and high-quality imagery. A conventional method for mixing the RGB lights has a lower rate of penetration and a lower mixing efficiency while having a higher power consumption of the conventional display panel, which hinders optimization of the display panel. Therefore, a pixel having a R subpixel, a G subpixel, a B subpixel, and a white (W) subpixel is produced. The RGBW pixel is used for improving the display quality of the conventional RGB display panel.
A display panel adopting the RGBW pixels has following advantages: (1) The resolution of the subpixels is increased by one fourth. (2) The rate of penetration of the pixels is increased by 50%. (3) The R, G, B, and W pixels have more eleven-sixteenths color than the R, G, and B pixels do. Conventionally, the transmission interface of a signal is a transmission interface having the R, G, and B pixels. Images shown on a display panel having the R, G, B, and W pixels are easily to be distorted if a data signal carrying the R, G, and B pixels is used in such a display panel. To work successfully, a data signal carrying the R, G, and B pixels needs to be transformed into a data signal carrying the R, G, B, and W pixels, and then the data signal carrying the R, G, B, and W pixels has to be input to corresponding subpixels in the display panel.
Currently, the method for transforming a data signal carrying the R, G, and B pixels into a data signal carrying the R, G, B, and W pixels is as follows:
Firstly, obtaining the grayscale values R, G, and B which the data signal carrying the R, G, and B pixels corresponds to; next, calculating the corresponding grayscale values R′, G′, B′, and W′ which the data signal carrying the R, G, B, and W pixels corresponds to based on Equation (1) and Equation (2).
                                                        X              ′                        +                          min              ⁡                              (                                  R                  ,                  G                  ,                  B                                )                                                                        max              ⁡                              (                                  R                  ,                  G                  ,                  B                                )                                      +                          min              ⁡                              (                                  R                  ,                  G                  ,                  B                                )                                                    =                  X                      max            ⁡                          (                              R                ,                G                ,                B                            )                                                          (        1        )                                          W          ′                =                  min          ⁡                      (                          R              ,              G              ,              B                        )                                              (        2        )            
X needs to be the grayscale value R, G, or B. The min(R, G, B) is the minimum value among the grayscale values R, G, and B. The max(R, G, B) is the maximum value among the grayscale values R, G, and B in both of Equation (1) and Equation (2).
Based on the above-mentioned transformation method, the grayscale values R′, G′, B′, and W′ are obtained at once after the grayscale values R, G, and B are calculated. Using the obtained grayscale values R′, G′, B′, and W′, it is not possible to maintain as good chromaticity and saturation as when the original grayscale values R, G, and B are used.